The present invention relates to the formation of semiconductor devices. More specifically, the invention relates to an apparatus or method for removing liquids from a substrate during the formation of semiconductor devices.
During semiconductor wafer processing, wet processing requires the subsequent removal of liquid from semiconductor devices.
As semiconductor devices continue to scale down to smaller sizes, higher aspect ratio structures are required to achieve the desired device performance. The fabrication of microelectronic/semiconductor devices requires a repetitive flow of multiple processing steps such as, material deposition, planarization, feature patterning, feature etching, and feature cleaning. The drive towards higher aspect ratio structures creates processing challenges for many of these traditional fabrication steps. Wet processes such as etch and clean, which typically make up greater than ˜25% of the process flow, are particularly challenging on high aspect ratio features due to the capillary forces that are generated during drying. The strength of these capillary forces are dependent on the surface tension and contact angle of the etch, clean, or rinse fluids that are being dried, as well as the feature spacing and aspect ratio. If the forces generated during drying are too high, then the high aspect ratio features will collapse onto each other and stiction may occur. Feature collapse and stiction will severely degrade the device yield.
In addition, the formation of capacitors may also provide structures that are subject to collapse during drying.